Diphenyl sulfone compounds, and their production and use

ABSTRACT

A compound of the formula: ##STR1## wherein R is a hydrogen atom or a lower alkoxy group and X and Y are, the same or different, each a hydrogen atom, a halogen atom, a lower alkyl group, a lower alkoxy group, a carboxy(lower)alkoxy group or a lower alkoxycarbonyl(lower)alkoxy group, which is useful as a herbicide.

The present invention relates to diphenyl sulfone compounds, and theirproduction and use. More particularly, it relates to novel diphenylsulfone compounds bearing a 2-chloro-4-trifluoromethylphenoxy group onthe benzene ring, and their preparation processes and their use asherbicides.

The said diphenyl sulfone compounds are representable by the formula:##STR2## wherein R is a hydrogen atom or a lower alkoxy group and X andY are, the same or different, each a hydrogen atom, a halogen atom, alower alkyl group, a lower alkoxy group, a carboxy(lower)alkoxy group ora lower alkoxycarbonyl(lower)alkoxy group.

Among them, preferred are those of the formula: ##STR3## wherein R' is alower alkoxy group and X' is a hydrogen atom, a halogen atom, a loweralkyl group or a lower alkoxy group. Particularly preferred are those ofthe formulas: ##STR4##

Throughout the specification, the term "lower" is intended to mean anygroup having not more than four carbon atoms, unless otherwise defined.The term "halogen" may include chlorine, bromine, iodine and fluorine.

Some diphenyl sulfone compounds are disclosed in Gazz. Chim. Ital., 91,223 (1961), but this literature reference is entirely silent on whetherthey have any herbicidal activity.

It has now been found that the diphenyl sulfone compounds of the formula(I) exert a strong herbicidal activity against a wide variety of weedswhich may cause a serious damage on important crop plants such as riceplants, corn, wheat and soybean by pre-emergence treatment as well aspost-emergence treatment.

Namely, when applied to paddy fields by foliar and/or soil treatment inpre-emergence or post-emergence, the diphenyl sulfone compounds (I) canprevent and exterminate monocotyledonous weeds including Gramineae weedssuch as barnyardgrass (Echinochloa crus-galli) and annual Cyperaceaeweeds such as rice flatsedge (Cyperus sp.) and small flower umbrellaplant (Cyperus difformis), broad-leaved weeds such as false pimpernel(Lindernia pyxidaria), Vandellia angustifolia, Dopatrium junceum,monochoria (Monochoria vaginalis), toothcup (Rotala indica) and Longstemmed waterwort (Elatine triandra), perennial weeds such as arrowhead(Sagittaria pygmaea), etc.

Further, when applied to farmlands by foliar and/or soil treatment inpre-emergence or post-emergence, they prevent and exterminatebroad-leaved weeds such as common lambsquarters (Chenopodium album),velvetleaf (Abtilon theophrasti), tall morningglory (Ipoea purpurea),redroot pigweed (Amaranthus retroflexus) and wild buckwheat (Polygonumconvolvulus), narrow-leaved weeds such as flatsedge (Cyperus sp.),barnyardgrass, (Echinochloa crus-galli), green foxtail (Setariaviridis), large crabgrass (Digitaria sanguinalis), fall panicum (Panicumdichotomiflorum), goosegrass (Eleusine indica), downy brome (Bromustectorum) and quackgrass (Aqropyron repens), etc. At the practical dose,they do not produce any material phytotoxicity on crop plants such asrice plants, corn, wheat and barley. Thus, they are useful as herbicidesapplicable to paddy fields and farmlands.

Besides, due to their high herbicidal potency and broad herbicidalspectrum, they may be used as herbicides for orchards, non-agriculturalfields, forests, etc.

The diphenyl sulfone compounds (I) are per se novel and may be producedby various procedures, of which typical examples are as follows:

Procedure (A)

A benzenesulfonyl halide compound of the formula: ##STR5## wherein X₁ isa halogen atom (e.g. chlorine, bromine) is reacted with a benzenecompound of the formula: ##STR6## wherein X and Y are each as definedabove in the presence of a Lewis acid to give the diphenyl sulfonecompound of the formula: ##STR7## wherein X and Y are each as definedabove.

The starting benzenesulfonyl halide compound (IIA) is obtainable byreacting 2-chloro-4-trifluoromethyldiphenyl ether with chlorosulfonicacid or by reacting 2-chloro-4-trifluoromethylphenoxybenzenesulfonicacid with a halogenating agent such as thionyl chloride or phosphoruspentachloride.

The reaction between the2-chloro-4-trifluoromethylphenoxybenzenesulfonyl halide (IIA) and thebenzene compound (IIIA) may be carried out in the presence of a Lewisacid as the catalyst, if necessary, in the coexistence of an inertsolvent (e.g. dichloroethane, nitrobenzene, carbon disulfide), usuallyat a temperature of 30° to 150° C., preferably of 50° to 120° C.Examples of the Lewis acid are anhydrous ferric chloride, anhydrous tinchloride, etc. The objective diphenyl sulfone compound (IA) isobtainable in a good yield.

Procedure (B)

A diphenyl sulfide compound of the formula: ##STR8## wherein X₂ and Y₂are, the same or different, each a hydrogen atom, a halogen atom, alower alkyl group or a lower alkoxy group and R is as defined above isreacted with an oxidizing agent to give the diphenyl sulfone compound ofthe formula: ##STR9## wherein R, X₂ and Y₂ are each as defined above.

The reaction may be carried out by treatment of the diphenyl sulfidecompound (IIB) with an oxidizing agent in an inert solvent (e.g. aceticacid, acetone, water) usually at a temperature of 0° to 120° C.,preferably of 30° to 100° C. Examples of the oxidizing agent arehydrogen peroxide, manganese peroxide, organic peracids (e.g. peraceticacid, m-chloroperbenzoic acid), etc. The objective diphenyl sulfonecompound (IB) is obtainable in a good yield.

Procedure (C)

A 1,3-diphenoxydiphenyl sulfone compound of the formula: ##STR10##wherein X₃ is a hydrogen atom, a halogen atom, a lower alkyl group or alower alkoxy group is reacted with an alkanol of the formula:

    R.sub.1 OH                                                 (IIIC)

wherein R₁ is a lower alkyl group in the presence of a base to give thediphenyl sulfone compound of the formula: ##STR11## wherein R₁ and X₃are each as defined above.

The reaction between the 1,3-diphenoxydiphenyl sulfone compound (IIC)and the alkanol (IIIC) may be carried out in the presence of a base suchas an inorganic base (e.g. sodium hydroxide, potassium hydroxide), ifnecessary, in the coexistence of an inert solvent (e.g. tetrahydrofuran,dioxane), usually at a temperature of 50° to 150° C., preferably of 50°to 120° C., whereby the objective diphenyl sulfone compound (IC) isobtainable in a good yield.

Among the starting materials used in the above procedures, the diphenylsulfide compound (IIB) and the 1,3-diphenoxydiphenyl sulfone compound(IIC) are per se novel. The diphenyl sulfide compound (IIB) may beproduced by reacting an aniline compound of the formula: ##STR12##wherein R is as defined above with a thiophenol compound of the formula:##STR13## wherein X₂ and Y₂ are each as defined above in the manner asdisclosed in Gazz. Chim. Ital., 91, 223 (1961).

The 1,3-diphenoxydiphenyl sulfone compound (IIC) may be produced byreacting a 1,3-diphenoxybenzene compound of the formula: ##STR14## witha benzenesulfonyl compound of the formula: ##STR15## wherein X₃ is asdefined above in an inert solvent in the presence of a Friedel-Craftcatalyst. This 1,3-diphenoxybenzene compound (VI) is disclosed inJapanese Patent Publication (unexamined) No. 236/1974.

Practical embodiments of the preparation procedures as generallydescribed above will be illustratively shown in the following Exampleswhere % is by weight.

EXAMPLE 1

To a solution of 2-chloro-4-trifluoromethylphenoxybenzenesulfonylchloride (2 g) in benzene (20 ml), anhydrous ferric chloride (0.96 g)was added, and the resultant mixture was refluxed for 2 hours. Thereaction mixture was washed with 5% hydrochloric acid, dried overanhydrous magnesium sulfate and concentrated. The residue wascrystallized from ethanol to give2-chloro-4-trifluoromethylphenoxydiphenyl sulfone (Compound No. 1) (1.6g). M.P., 91.5°-93° C.

EXAMPLE 2

To a mixture of 4-(2-chloro-4-trifluoromethylphenoxy)-2-ethoxyaniline(34 g), water (150 ml) and conc. hydrochloric acid (30 ml) kept at atemperature of 0° to 5° C., a solution of sodium nitrate (7.8 g) inwater (30 ml) was dropwise added, and the resultant mixture was stirredfor 20 minutes. This mixture was neutralized with sodium acetate andadded dropwise to a mixture of powdery copper (0.3 g),p-methoxybenzenethiol (14.4 g), sodium hydroxide (4.1 g) and water (50ml) kept at 40° C. The resulting mixture was stirred at 100° C. for 2hours. The reaction mixture was extracted with ether. The extract waswashed with 5% sodium hydroxide solution, water, 5% hydrochloric acidand water in order, dried over anhydrous magnesium sulfate andconcentrated. The residual oil was chromatographed on silica gel to give4-(2-chloro-4-trifluoromethylphenoxy)-2-ethoxy-4'-methoxydiphenylsulfide (40 g) as an oil.

The oil was dissolved in acetic acid (200 ml), and 30% hydrogen peroxide(56 g) was dropwise added thereto at room temperature (about 25° C.)while stirring. Then, stirring was continued at 50° C. for 3 hours. Tothe reaction mixture, 5% sodium thiosulfate solution was added, followedby concentration. The concentrate was extracted with toluene. Theextract was washed with 5% sodium hydroxide solution and water in order,dried over anhydrous magnesium sulfate and concentrated. The residualoil was chromatographed on silica gel. The obtained oil was treated withethanol, and the precipitated crystals were recrystallized from ethanolto give4-(2-chloro-4-trifluoromethylphenoxy)-2-ethoxy-4'-methoxydiphenylsulfone (Compound No. 23) (11.4 g). M.P., 101°-102° C.

EXAMPLE 3

To a solution of 1,3-bis(2-chloro-4-trifluoromethylphenoxy)benzene (9 g)and p-methoxybenzenesulfonyl chloride (4.4 g) in 1,2-dichloroethane (100ml), anhydrous ferric chloride (3.7 g) was added at room temperature,and the resultant mixture was warmed until the generation of gas ceased.The reaction mixture was admixed with 5% hydrochloric acid. The organicsolvent layer was separated, washed with water and concentrated. Theobtained oil was allowed to stand overnight to solidify. The resultantsolid was washed with a mixture of toluene and hexane, and the resultingcrystals were recrystallized from ethanol to give1,3-bis(2-chloro-4-trifluoromethylphenoxy)-4'-methoxydiphenyl sulfone(5.3 g). M.P., 153°-155.5° C.

1,3-bis(2-chloro-4-trifluoromethylphenoxy)-4'-methoxydiphenyl sulfone(1.5 g) was dissolved in dioxane (20 ml), and a solution of potassiumhydroxide (1 g) in methanol (10 ml) was added thereto while stirring.The resultant mixture was heated at 60° C. until the reaction wascompleted. The reaction mixture was admixed with water and extractedwith toluene. The extract was washed with water, dried over anhydrousmagnesium sulfate and chromatographed on silica gel, whereby4-(2-chloro-4-trifluoromethylphenoxy)-2-methoxy-4'-methoxydiphenylsulfone (Compound No. 25) (0.68 g) was obtained as a resinous material.

Some examples of the diphenyl sulfone compound (I) prepared in the samemanner as above are shown in Table 1.

                                      TABLE 1                                     __________________________________________________________________________     ##STR16##                                                                    Compound                            Elementary analysis                       No.   R   X          Y    Physical Property                                                                           C  H  Cl S  Br                        __________________________________________________________________________    1     H   H          H    M.P. 91.5-93° C.                                                                 Calcd.                                                                            55.28                                                                            2.93                                                                             8.59                                                                             7.77                                                             Found                                                                             55.43                                                                            2.83                                                                             8.66                                                                             7.51                         2     H   4-CH.sub.3 H    M.P. 112-115° C.                                                                 Calcd.                                                                            56.01                                                                            3.76                                                                             8.27                                                                             7.48                                                             Found                                                                             56.28                                                                            3.68                                                                             8.37                                                                             7.45                         3     H   4-Cl       H    M.P. 86-87.5° C.                                                                 Calcd.                                                                            51.02                                                                            2.48                                                                             15.85                                                                            7.17                                                             Found                                                                             51.10                                                                            2.31                                                                             15.92                                                                            7.01                         4     H   4-Br       H    M.P. 87-88.5° C.                                                                 Calcd.                                                                            46.41                                                                            2.25                                                                             7.21                                                                             6.52                                                                             16.25                                                         Found                                                                             46.52                                                                            2.07                                                                             7.31                                                                             6.34                                                                             16.02                     5     H   4-F        H    M.P. 105-106.5° C.                                                               Calcd.                                                                            52.97                                                                            2.57                                                                             8.23                                                                             7.44                                                             Found                                                                             53.12                                                                            2.60                                                                             7.94                                                                             7.33                         6     H   4-OCH.sub.3                                                                              H    M.P. 80.5-84° C.                                                                 Calcd.                                                                            54.25                                                                            3.19                                                                             8.01                                                                             7.24                                                             Found                                                                             54.17                                                                            3.05                                                                             8.17                                                                             7.13                         7     H   4-OC.sub.2 H.sub.5                                                                       H    M.P. 101-105° C.                                                                 Calcd.                                                                            55.21                                                                            3.53                                                                             7.76                                                                             7.02                                                             Found                                                                             55.37                                                                            3.39                                                                             8.06                                                                             6.89                         8     H   4-OCH.sub.3                                                                              2-OCH.sub.3                                                                        M.P. 113-114° C.                                                                 Calcd.                                                                            54.50                                                                            3.30                                                                             7.31                                                                             6.61                                                             Found                                                                             54.38                                                                            3.40                                                                             7.59                                                                             6.36                         9     H   4-OC.sub.2 H.sub.5                                                                       2-OC.sub.2 H.sub.5                                                                 M.P. 104-105° C.                                                                 Calcd.                                                                            55.15                                                                            4.02                                                                             7.08                                                                             6.40                                                             Found                                                                             55.20                                                                            4.10                                                                             7.15                                                                             6.34                         10    H   4-CH.sub.3 2-OCH.sub.3                                                                        M.P. 103.5-105° C.                                                               Calcd.                                                                            55.21                                                                            3.53                                                                             7.76                                                                             7.02                                                             Found                                                                             55.23                                                                            3.37                                                                             7.96                                                                             6.87                         11    H   4-OCH.sub.3                                                                              2-CH.sub.3                                                                         M.P. 100-101° C.                                                                 Calcd.                                                                            55.21                                                                            3.53                                                                             7.76                                                                             7.02                                                             Found                                                                             55.16                                                                            3.45                                                                             8.01                                                                             7.20                         12    H                                                                                  ##STR17## H    Resinous  Calcd. Found                                                                      53.65 53.70                                                                      3.52 3.51                                                                        6.89  6.95                                                                       6.23 6.08                    13    H                                                                                  ##STR18## H    n.sup.26 1.5454                                                                         Calcd. Found                                                                      55.30 55.57                                                                      4.08 3.92                                                                        6.53 6.76                                                                        5.91 5.68                    14    H                                                                                  ##STR19## H    Resinous  Calcd. Found                                                                      52.76 52.53                                                                      3.22 3.19                                                                        7.08 6.85                                                                        6.40 6.58                    15    H   4-OCH.sub.2 COOCH.sub.3                                                                  H    M.P. 136.5-137.5° C.                                                             Calcd.                                                                            52.76                                                                            3.22                                                                             7.08                                                                             6.40                                                             Found                                                                             52.89                                                                            3.51                                                                             6.79                                                                             6.12                         16    OC.sub.2 H.sub.5                                                                  H          H    M.P. 116.5-117.5° C.                                                             Calcd.                                                                            55.21                                                                            3.53                                                                             7.76                                                                             7.02                                                             Found                                                                             55.31                                                                            3.49                                                                             8.02                                                                             6.88                         17    OC.sub.2 H.sub.5                                                                  4-CH.sub.3 H    M.P. 116-117.5° C.                                                               Calcd.                                                                            56.12                                                                            3.85                                                                             7.53                                                                             6.81                                                             Found                                                                             55.91                                                                            3.76                                                                             7.72                                                                             6.52                         18    OC.sub.2 H.sub.5                                                                  H          3-CH.sub.3                                                                         M.P. 127-128.5° C.                                                               Calcd.                                                                            56.12                                                                            3.85                                                                             7.53                                                                             6.81                                                             Found                                                                             56.14                                                                            3.63                                                                             7.52                                                                             6.75                         19    OC.sub.2 H.sub.5                                                                  H          2-CH.sub.3                                                                         M.P. 139-141°  C.                                                                Calcd.                                                                            56.12                                                                            3.85                                                                             7.53                                                                             6.81                                                             Found                                                                             56.07                                                                            3.77                                                                             7.57                                                                             7.07                         20    OC.sub.2 H.sub.5                                                                  4-Cl       H    M.P. 105.5-107° C.                                                               Calcd.                                                                            51.34                                                                            3.08                                                                             14.43                                                                            6.35                                                             Found                                                                             51.62                                                                            3.05                                                                             14.39                                                                            6.12                         21    OC.sub.2 H.sub.5                                                                  4-Br       H    M.P. 110.5-115° C.                                                               Calcd.                                                                            47.08                                                                            2.82                                                                             6.62                                                                             5.98                                                                             14.91                                                         Found                                                                             47.04                                                                            2.80                                                                             6.33                                                                             5.61                                                                             14.78                     22    OC.sub.2 H.sub.5                                                                  4-F        H    M.P. 142-144.5° C.                                                               Calcd.                                                                            53.12                                                                            3.18                                                                             7.47                                                                             6.75                                                             Found                                                                             53.19                                                                            3.20                                                                             7.56                                                                             6.56                         23    OC.sub.2 H.sub.5                                                                  4-OCH.sub.3                                                                              H    M.P. 101-102° C.                                                                 Calcd.                                                                            54.27                                                                            3.73                                                                             7.28                                                                             6.59                                                             Found                                                                             54.33                                                                            3.61                                                                             7.06                                                                             6.47                         24    OC.sub.2 H.sub.5                                                                  4-OC.sub.2 H.sub.5                                                                       H    Resinous  Calcd.                                                                            55.15                                                                            4.02                                                                             7.08                                                                             6.40                                                             Found                                                                             54.92                                                                            3.83                                                                             7.32                                                                             6.47                         25    OCH.sub.3                                                                         4-OCH.sub.3                                                                              H    Resinous  Calcd.                                                                            53.34                                                                            3.41                                                                             7.50                                                                             6.78                                                             Found                                                                             53.46                                                                            3.25                                                                             7.54                                                                             7.06                         __________________________________________________________________________

In the practical usage of the diphenyl sulfone compound (I), it may beapplied as such or in any preparation form as conventionally adopted inthe related art field (e.g. dust, crude dust, fine granule, granule,wettable powder, emulsifiable concentrate, flowable, solution,suspension).

For formulation of said preparations, solid or liquid carriers ordiluents may be used. The terms "carriers and diluents" as herein usedare intended to mean natural or synthetic organic or inorganicsubstances which are used in a mixture with the active ingredient inorder to assist the reach and contact of the active ingredient to thepart to be treated and/or to make easy the storage, transportation andtreatment of the active ingredient.

The dust may usually comprise the active ingredient in a solid carrierin a concentration of about 1 to 25% by weight. The wettable powdercomprises normally the active ingredient in a solid carrier and adispersing or wetting agent optionally with a protective colloidalagent, a thixotropic agent, an antifoaming agent, etc. in aconcentration of about 25 to 90% by weight. The granules may comprisethe active ingredient in a solid carrier in a concentration of about 0.5to 35% by weight, the active ingredient being uniformly dispersed in thecarrier or being fixed or adsorbed evenly at the surfaces of thecarrier, and have a particle size of about 0.2 to 1.5 mm. Theemulsifiable concentrate may include normally the active ingredient in aliquid carrier comprising about 5 to 20% by weight of an emulsifier in aconcentration of about 5 to 50% by weight.

As for the solid carrier or diluent, there may be exemplified mineralpowders (e.g. kaolin, bentonite, clay, montmorillonite, talc,diatomaceous earth, mica, vermiculite, gypsum, calcium carbonate,apatite), vegetable powders (e.g. soybean powder, flour, wooden powder,tobacco powder, starch, crystalline cellulose), high molecular weightcompounds (e.g. petroleum resin, polyvinyl chloride, dammar gum, ketoneresin), alumina, wax and the like. As for the liquid carrier or diluent,there may be exemplified alcohols (e.g. methanol, n-hexanol, ethyleneglycol, diethylene glycol, cyclohexanol, benzyl alcohol), ether alcohols(e.g. ethylene glycol ethyl ether, ethylene glycol phenyl ether,diethylene glycol ethyl ether, diethylene glycol butyl ether),paraffinic or naphthenic hydrocarbons (e.g. kerosene, mineral oil,spindle oil, white oil), aromatic hydrocarbons (e.g. benzene, toluene,xylene, ethylbenzene, cumene, methylnaphthalene), halogenatedhydrocarbons (e.g. carbon tetrachloride, chloroform, trichloroethylene,monochlorobenzene, o-chlorotoluene), ethers (e.g. dioxane,tetrahydrofuran), ketones (e.g. acetone, methylethylketone,diisobutylketone, cyclohexanone, acetophenone, isophorone), esters (e.g.ethyl acetate, amyl acetate, ethylene glycol acetate, diethylene glycolacetate, dibutyl maleate, diethyl succinate), dimethylformamide,dimethylsulfoxide, water, etc.

A surface active agent used for emulsifying, dispersing, wetting,spreading, binding, break-controlling, stabilizing,flowability-improving, rust-preventing, etc. may be any of thenon-ionic, anionic, cationic and amphoteric type of agents. Examples ofthe non-ionic surface active agent are additive polymerization productsof ethylene oxide to higher alcohols (e.g. lauryl alcohol, stearylalcohol, oleyl alcohol), additive polymerization products of ethyleneoxide to alkylphenols (e.g. isooctylphenol, nonylphenol), additivepolymerization products of ethylene oxide to alkylnaphthols (e.g.butylnaphthol, octylnaphthol), additive polymerization products ofethylene oxide to higher fatty acids (e.g. palmitic acid, stearic acid,oleic acid), additive polymerization products of ethylene oxide tomonoalkyl or dialkyl phosphates (e.g. stearyl phosphate, dilaurylphosphate), additive polymerization products of ethylene oxide to amines(e.g. dodecylamine, stearylamide), higher fatty acid esters ofpolyvalent alcohols (e.g. sorbitan) and additive polymerization productsof ethylene oxide thereto, additive polymerization products of ethyleneoxide and propylene oxide, etc. Examples of the anionic surface activeagent are alkylsulfates (e.g. sodium laurylsulfate, amine salts of oleylalcohol sulfuric esters), alkylsulfonates (e.g. sodium sulfosuccinicacid dioctyl ester, sodium 2-ethylhexylsulfonate), arylsulfonates (e.g.sodium isopropylnaphthalenesulfonate, sodiummethylenebisnaphthalenesulfonate, sodium ligninsulfonate, sodiumdodecylbenzenesulfonate), etc.

Besides, any other auxiliary agent(s) may be used in order to improvethe properties of the preparations and enhance the biological effect ofthe preparations. Examples of the auxiliary agent are casein, gelatin,albumin, glue, sodium alginate, carboxymethylcellulose, methylcellulose,hydroxyethylcellulose, polyvinyl alcohol, etc.

In the herbicidal composition of this invention, the content of thediphenyl sulfone compound (I) as the active ingredient may be usuallyfrom 0.1 to 95% by weight, preferably from 0.5 to 90% by weight,although its favorable content varies within a wide range depending uponthe type of formulation as hereinbefore stated.

Practical embodiments of the herbicidal composition according to theinvention are illustratively shown in the following Examples whereinpart(s) and % are by weight.

FORMULATION EXAMPLE 1

In a mixer, Compound No. 5 (4 parts), clay (66 parts) and bentonite (30parts) are mixed uniformly. To the mixture, a suitable amount of wateris added, and the resulting mixture is kneaded in a kneader. Theresultant mixture is extruded through a screen of 0.8 mm in mesh size,and the extruded granules are dried in a dryer at 50° C. to give agranule containing 4% of the active ingredient.

FORMULATION EXAMPLE 2

In a mixer, Compound No. 23 (2 parts), clay (90 parts), talc (3 parts)and sodium ligninsulfonate (5 parts) are mixed uniformly. After additionof a suitable amount of water, the resultant mixture is kneaded in akneader and then extruded through a screen of 0.8 mm in mesh size,followed by drying in a dryer at 50° C. to give a granule containing 2%of the active ingredient.

FORMULATION EXAMPLE 3

Compound No. 20 (50 parts), clay (30 parts), diatomaceous earth (10parts), white carbon (5 parts) and sodium alkylbenzenesulfonate (5parts) are pulverized and mixed well to give a wettable powdercontaining 50% of the active ingredient.

FORMULATION EXAMPLE 4

Compound No. 24 (20 parts), xylene (45 parts) and "Sorpol SM100" (asurface active agent manufactured by Toho Kagaku K.K.) (15 parts) aremixed together to give an emulsifiable concentrate containing 20% of theactive ingredient.

The dosage of the herbicide of the invention depends upon the kind ofthe active ingredient, the sort of the cultivated plants, the method ofapplication, the weather, etc. When, for instance, the herbicide isapplied to paddy fields or farmlands in pre-emergence or post-emergenceof weeds by soil treatment, its amount may be from about 5 to 2000 grams(as the active ingredient) per 10 ares. In order to exterminate weeds innon-agricultural fields such as roads and play grounds, its amount maybe from about 20 to 4000 grams (as the active ingredient) per 10 ares.

The diphenyl sulfone compound (I) may be used together with otherherbicides to improve its activity as the herbicide, and in some cases,to produce a synergistic effect. As the herbicides to be mixedtherewith, there may be mentioned triazine series herbicides such as2-methylthio-4,6-bisethylamino-1,3,5-triazine,2-chloro-4,6-bisethylamino-1,3,5-triazine,2-methylthio-4-ethylamino-6-(1,2-dimethylpropyl)amino-s-triazine,2-methoxy-4-ethylamino-6-isopropylamino-1,3,5-triazine,2-chloro-4-ethylamino-6-isopropylamino-s-triazine,2-methylthio-4,6-bis(isopropylamino)-s-triazine,2-methylthio-4-ethylamino-6-isopropylamino-s-triazine,4-amino-6-tert.-butyl-3-(methylthio)-1,2,4-triazin-5(4H)-one; phenoxyseries herbicides such as 2,4-dichlorophenoxyacetic acid and its methyl,ethyl or butyl ester, 4-chloro-2-methylphenoxyacetic acid, ethyl2-methyl-4-chlorophenoxybutylate; diphenyl ether series herbicides suchas 2,4,6-trichlorophenyl-4'-nitrophenyl ether,2,4-dichlorophenyl-4'-nitrophenyl ether,2,4-dichlorophenyl-4'-nitro-3'-methoxyphenyl ether; urea seriesherbicides such as 3-(3,4-dichlorophenyl)-1-methoxy-1-methylurea,3-(3,4-dichlorophenyl)-1,1-dimethylurea,1-(α,α-dimethylbenzyl)-3-(4-tolyl)urea,N-[4-(4-methylphenethyloxy)phenyl]-N'-methyl-N'-methoxyurea,3-(4-chlorophenyl)-1,1-dimethylurea; carbamate series herbicides such as3-methoxycarbonylaminophenyl N-(3-methylphenyl)carbamate, isopropylN-(3-chlorophenyl)carbamate, methyl N-(3,4-dichlorophenyl)carbamate;uracil series herbicides such as 5-bromo-3-sec.-butyl-6-methyluracil,1-cyclohexyl-3,5-propylene uracil; thiol carbamate series herbicidessuch as S-(4-chlorobenzyl) N,N-diethylthiolcarbamate, S-ethylN-cyclohexyl-N-ethylthiolcarbamate, S-ethylhexahydro-1H-azepin-1-carbothioate, S-ethylN,N-di-n-propylthiolcarbamate; pyridinium chloride series herbicidessuch as 1,1'-dimethyl-4,4'-bispyridinium dichloride; phosphorus seriesherbicides such as N-(phosphonomethyl)glycin,O-ethyl-O-(2-nitro-5-methylphenyl)-N-sec.-butylphosphoroamidothioate;aniline series herbicides such asα,α,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine,4-(methylsulfonyl)-2,6-dinitro-N,N-dipropylaniline; acid anilide seriesherbicides such as 2-chloro-2',6'-diethyl-N-(butoxymethyl)acetanilide,n-butyl-N-chloroacetyl-2,6-diethylanilinoacetate,2-chloro-2',6'-diethyl-N-(methoxymethyl)acetanilide,3,4-dichloropropionanilide,N-(α,α-dimethylbenzyl)-α-bromo-tert.-butylacetamide;5-tert.-butyl-3-(2,4-dichloro-5-isopropoxyphenyl)-1,3,4-oxadiazolin-2-one;2-(α-naphthoxy)-N,N-diethylpropionamide;1,3-dimethyl-4-(2,4-dichlorobenzoyl)-5-pyrazolyl-p-toluenesulfonate;3-isopropyl-benzo-2-thia-1,3-diazinon-(4)-2,2-dioxide;3-(2-methylphenoxy)pyridazine, etc.

The herbicides of the invention may be applied together with fungicides,microbial pesticides, pyrethroidal insecticides, other insecticides,plant growth regulators, fertilizers, etc.

Some test examples which show the herbicidal activity of the diphenylsulfone compound (I) are shown in the following Examples wherein % is byweight.

EXAMPLE I

Into polyethylene-made pots of 70 cm² in surface area, paddy field soilwas filled. Seeds of barnyardgrass (Panicum crus-galli) and broad-leavedweeds such as monochoria, false pimpernel, toothcup and Dopatriumjunceum were mixed into the soil. The pots were flooded with water tomake a paddy field condition. In each of the pots, two bulbs ofarrowhead were planted. Then, rice plants at the two or three foliatestage were transplanted into the pots. Cultivation was carried out in agreenhouse at 25° to 30° C. On the 2nd day after the transplantation,the test compound formulated in an emulsifiable concentrate and dilutedwith water was applied to the pots in an amount of 10 ml per pot by soiltreatment. Cultivation was further continued in the greenhouse. On the25th day from the soil treatment, the herbicidal effect and thephytotoxicity were determined on the following criteria:

Herbicidal effect:

    ______________________________________                                        Evaluation      Prevention percentage (%)                                     ______________________________________                                        0               0-19                                                          1               20-39                                                         2               40-59                                                         3               60-79                                                         4               80-99                                                         5               100 (completely dead)                                         ______________________________________                                    

Phytotoxicity to rice plants:

    ______________________________________                                        Evaluation     Remarks                                                        ______________________________________                                        0              No phytotoxicity                                               1              Slight phytotoxicity observed                                                 but no material influence on                                                  growth                                                         2              Growth once influenced but                                                    recovered; no material                                                        reduction in crop                                              3              Growth and crop slightly                                                      influenced                                                     4              Growth and crop influenced                                     5              Completely dead                                                ______________________________________                                    

The results are shown in Table 2.

                  TABLE 2                                                         ______________________________________                                        Dosage                                                                        (weight of    Herbicidal activity                                                                              Phyto-                                               active in-          Broad-       toxicity                             Compound                                                                              gredient, Barnyard- leaved                                                                              Arrow- Rice                                 No.     g/are)    grass     weed  head   plant                                ______________________________________                                        1       5         3         5     5      0                                            10        5         5     5      0                                    2       5         4         5     5      0                                            10        5         5     5      0                                    4       2.5       5         5     5      0                                            5         5         5     5      0                                    5       5         3         5     5      0                                            10        4         5     5      0                                    6       2.5       5         5     3      0                                            5         5         5     4      0                                    8       2.5       5         5     5      0                                            5         5         5     5      0                                    10      5         4         5     3      0                                            10        5         5     4      0                                    11      5         3         5     4      0                                            10        4         5     5      0                                    13      10        3         5     5      0                                            20        5         5     5      0                                    14      10        3         5     5      0                                            20        4         5     5      0                                    16      5         5         5     3      0                                            10        5         5     4      0                                    17      10        5         5     2      0                                            20        5         5     4      0                                    18      10        5         5     2      0                                            20        5         5     4      0                                    20      10        5         5     2      0                                            20        5         5     4      0                                    21      5         5         5     3      0                                            10        5         5     4      0                                    22      10        5         5     2      0                                            20        5         5     4      0                                    23      2.5       5         5     5      0                                            5         5         5     5      0                                    25      2.5       5         5     5      0                                            5         5         5     5      0                                    Control 2.5       1         2     0      0                                    (a)*.sup.(1)                                                                          5         3         4     1      0                                    Control 2.5       0         1     0      0                                    (b)*.sup.(2)                                                                          5         2         4     0      0                                    Control 5         4         4     0      0                                    (c)*.sup.(3)                                                                          10        4         4     0      0                                    ______________________________________                                         Note                                                                          *.sup.(1) 2,4-Dichlorophenyl-4'-nitro-3'-methoxyphenyl ether                  *.sup.(2) 2,4,6-Trichlorophenyl-4'-nitro-phenyl ether                         *.sup.(3) 4-(4-chlorophenoxy)-4'-chloro-diphenyl sulfone                 

EXAMPLE II

Into polyethylene-made trays of 700 cm² in surface area, farmland soilwas filled. Seeds of corn, rice plant and wheat as well as seeds ofcommon lambsquarters, velvetleaf, tall morningglory, redroot pigweed,wild buckwheat and black nightshade (Solanum nigrum) were sowed therein.Two to three weeks thereafter, the test compound formulated in anemulsifiable concentrate and diluted with water was sprayed to the traysin an amount of 5 liters per are by foliar treatment. On the 20th dayafter the foliar treatment, the herbicidal effect and the phytotoxicitywere determined as in Example I.

The results are shown in Table 3.

                                      TABLE 3                                     __________________________________________________________________________    Dosage                                                                        (weight of  Herbicidal activity                                               active in-  Common    Tall            Black                                                                             Phytotoxicity                       Compound                                                                            gredient,                                                                           lambs-                                                                             Velvet-                                                                            morning-                                                                           Redroot                                                                            Wild buck-                                                                          night-                                                                            Rice                                No.   g/are)                                                                              quarters                                                                           leaf glory                                                                              pigweed                                                                            wheat shade                                                                             plant                                                                            Corn                                                                             Wheat                         __________________________________________________________________________     3    5     4    5    4    5    5     5   0  0  0                                   10    5    5    5    5    5     5   0  0  0                              9    5     3    5    5    5    2     3   0  0  0                                   10    4    5    5    5    4     4   0  0  0                             23    2.5   5    5    5    5    5     5   0  0  0                                   5     5    5    5    5    5     5   0  0  0                             24    2.5   5    5    5    5    5     5   0  0  0                                   5     5    5    5    5    5     5   0  0  0                             Control                                                                             2.5   2    1    1    1    0     5   1  1  1                             (a)   5     4    4    4    3    3     5   1  1  1                             Control                                                                             2.5   0    0    0    0    0     0   0  0  0                             (c)   5     0    0    0    0    0     0   0  0  0                             Un-   --    0    0    0    0    0     0   0  0  0                             treated                                                                       __________________________________________________________________________

EXAMPLE III

Into plastic trays (35×25×10 cm), farmland soil was filled, and seeds ofcommon purslane (Portulaca oleracea), corn and soybean were sowed,followed by covering with the soil. The test compound formulated in anemulsifiable concentrate and diluted with water was applied to the traysin an amount of 3 liters per are by spraying over the top. Cultivationwas continued in a greenhouse for 20 days. Then, the herbicidal effectand the phytotoxicity were determined as in Example I.

The results are shown in Table 4.

                  TABLE 4                                                         ______________________________________                                               Dosage                                                                        (weight of                                                                            Herbicidal                                                            active in-                                                                            activity                                                       Compound gredient, Common      Phytotoxicity                                  No.      g/are)    purslane    Corn Soybean                                   ______________________________________                                         8       10        5           0    0                                                  20        5           0    0                                         17       10        5           0    0                                                  20        5           0    0                                         23       10        5           0    0                                                  20        5           0    0                                         Control  10        0           0    0                                         (c)                                                                           Control  10        2           0    0                                         (d)*.sup.(1)                                                                           20        4           0    0                                         Un-      --        0           0    0                                         treated                                                                       ______________________________________                                         Note:                                                                         *.sup.(1) 2,4-Dichlorophenyl-3'-methoxy-carbonyl-4'-nitrophenyl ether    

EXAMPLE IV

Into plastic trays (35×25×10 cm), farmland soil was filled, and seeds ofsoybean, redroot pigweed, velvetleaf, cocklebur (Xanthiumpensylvanicum), tall morningglory and jimsonweed (Datura stramonium)were sowed. After being cultivated outdoors for 17 days, every two trayswere placed in a frame of 50 cm long, 100 cm wide and 40 cm high, andthe test compound formulated in an emulsifiable concentrate comprising aspreading agent and diluted with water to make 25 ml was applied theretoby spraying over the top. At this stage, the plants were generally atthe 1 to 4 foliar stage and of 2 to 20 cm in height. Cultivation wasfurther continued outdoors for 3 weeks. Then, the herbicidal effect andthe phytotoxicity were determined as in Example I.

The results are shown in Table 5.

                  TABLE 5                                                         ______________________________________                                        Dosage                                                                        (weight    Phyto-  Herbicidal activity                                              of active                                                                              toxi-   Red-             Tall                                  Com-  ingre-   city    root Vel-        morn- Jim-                            pound dient    Soy-    pig- vet- Cockle-                                                                              ing-  son-                            No.   g/are)   bean    weed leaf bur    glory weed                            ______________________________________                                        23    10       1       5    5    5      5     5                                     3        0       5    5    5      5     5                                     1        0       5    5    4      5     5                               24    10       1       5    5    5      5     5                                     3        1       5    5    5      5     5                                     1        0       5    5    4      4     5                               25    10       1       5    5    5      5     5                                     3        1       5    5    5      5     5                                     1        0       5    5    5      5     5                               Con-  10       1       5    5    5      5     5                               trol  3        1       5    5    4      5     5                               (e)*.sup.(1)                                                                        1        0       5    5    4      5     5                               ______________________________________                                         Note:                                                                         *.sup.(1) Commercially available herbicide known as "Acifluorfen", which      is representable by the formula:  -                                           ##STR20##                                                                

What is claimed is:
 1. A compound of the formula: ##STR21## wherein R isa hydrogen atom or a lower alkoxy group and X and Y, being the same ordifferent, are each a hydrogen atom, a halogen atom, a lower alkylgroup, a lower alkoxy group, a carboxy(lower)alkoxy group or a loweralkoxycarbonyl(lower)alkoxy group.
 2. The compound according to claim 1,which is represented by the formula: ##STR22## wherein R' is a loweralkoxy group and X' is a hydrogen atom, a halogen atom, a lower alkylgroup or a lower alkoxy group.
 3. The compound according to claim 1,which is represented by the formula: ##STR23##
 4. The compound accordingto claim 1, which is represented by the formula: ##STR24##
 5. Thecompound according to claim 1, which is represented by the formula:##STR25##
 6. The compound according to claim 1, which is represented bythe formula: ##STR26##
 7. The compound according to claim 1, which isrepresented by the formula: ##STR27##
 8. The compound according to claim1, which is represented by the formula: ##STR28##
 9. The compoundaccording to claim 1, which is represented by the formula: ##STR29## 10.A herbicidal composition which comprises as an active ingredient aherbicidally effective amount of the compound according to claim 1 andan inert carrier or diluent.
 11. A method for preventing orexterminating weeds which comprises applying a herbicidally effectiveamount of the compound according to claim 1 to the area where the weedsgrow or will grow.